Image compression describes the application of data compression to digital images. One reason for performing image compression is to reduce redundancy of image data in order to expediently store or transmit that data.
Image compression can be lossy or lossless. Since lossy compression approaches induce compression artifacts, lossless compression is often used for important or non-photographic images, such as medical imagery, or technical or other hand drawings. Lossy approaches, on the other hand, are often used for photographic images, since minor, often imperceptible losses of fidelity is typically an acceptable trade-off to achieving a reduction in bit rate.